It has long been known that a variety of chemical agents when introduced into the vaginal canal as suitable compositions will interfere with mammalian spermatic cells and prevent their ability to effect conception either by reducing the motility of such cells (i.e. a spermatostatic effect) or by cytotoxicity (i.e. a spermatocidal effect). In general, the types of agents most widely used for such purpose are alkylphenoxypolyethoxyethanols, quaternary ammonium compounds and organomercurial compounds. Recently a series of 1,2-benzisothiazole derivatives having powerful spermatocidal activity were described in U.S. Pat. No. 4,093,730.
In general such spermatostatic and spermatocidal compounds for vaginal administration show little if any effect upon spermatic cells when administered systemically to the male mammal. Furthermore, for such systemic administration a compound must not only have powerful spermatostatic or spermatocidal activity but must show a low degree of toxicity to the host mammal.
It would, therefore, be desirable to have agents for contraceptive purposes which inhibit mammalian sperm cells from effecting conception (and possibly also prevent sperm cell production or maturation in the case of male contraception), which agents could be administered either intravaginally to the female mammal or systemically, preferably orally or via an implant, to the male mammal.